MQ-8 Hydrogen Gas Sensor Module for Arduino

• using high-quality dual-panel design, with a power indicator and TTL signal output instructions;
• with a the DO switch signal (TTL) output, and AO analog signal output;
• TTL output valid signal is low. (When the low output signal light can be connected directly to the microcontroller or relay module)
• 0 ~ 5V analog output voltage, the higher the concentration, the higher the voltage.
• the hydrogen gas detection with better sensitivity.
• there are four screw holes for easy positioning;
• Product Dimensions: 32 (L) * 20 (W) * 22 (H)
• with a long life and reliable stability
• rapid response and recovery characteristics
• operating voltage: 5V

Module using the instructions:

Explanation: Use Preheat 20S

The first step: to the module for 5V DC (note the positive and negative do not reverse, otherwise easily burned chip).

Step 2: If you select the output end of the high and low DO, TTL output signal can be connected directly to a microcontroller IO port or connect to the relay module, potentiometer is used to adjust the output level transition threshold.

Step Three: If you choose to AO, analog output, so you do not have control potentiometer AO feet directly connected to the input of the AD converter or microcontroller with AD can. According to our experience: In a normal environment, namely: the environment of the measured gas, setting the sensor output voltage value of the reference voltage, At this time, the voltage of the AO end about 1V, when the sensor detects that the gas to be measured when the voltage of each elevated 0.1V, the actual measured gas concentrations 200ppm (simple: 1ppm = 1mg/kg = 1mg / L = 1 × 10-6 commonly used to indicate the gas concentration, or the concentration of the solution.), on the basis of this parameter can microcontroller inside the measured analog voltage value is converted to concentration values. Note: If you are used to do a precision instrument, please buy the standard calibration instrument market, or there is an error, because the ratio of the output concentration and voltage relationship is linear, but tends to be linear.

Special note: the sensor is powered Preheat 20S stable measurement data, sensor fever is a normal phenomenon, because the internal heating wire, if hot is not normal.